In recent years, the ORC (Organic Rankine Cycle) market expanded rapidly in terms of installed plants, produced power and number of ORC manufacturers. New markets, like waste heat recovery from industrial process or endothermic engines, are growing very fast, but the biomass combustion and the exploitation of geothermal brines have been confirmed as the two main fields of application. Especially for geothermal applications it is mandatory to maximize the plant efficiency in order to payback the relevant cost of exploration and drilling.
Exergy has introduced in the ORC market an interesting innovation by developing a radial outflow turbine that has several unique characteristics qualifying this unconventional configuration as advantageous for many ORC applications.
After a brief description of the radial outflow turbine and its main features, the paper discloses the field performances evaluation of two operating geothermal ORC plants installed by Exergy in Turkey. The work describes the test procedure, the measurements and calculation methods used to obtain the turbine efficiency as well as overall power cycle performance from the set of available experimental data.